This is a common polymorphism (HapMap 9.4% allele frequency) of a collagen gene. The SNP rs2228564 (c.977A>G) is ancestral to this one (c.976C>T), resulting in three common amino acids at this position: “CAG” codon = Gln/Q, “CGG” codon = Arg/R, and “TGG” codon = Trp/W. The interpretation of this polymorphism compared to reference in the absence of its neighboring polymorphism results it being misinterpreted as “Stop/X” (TAG), it should be “Trp/W”.